Always difficult to design right, the first time. Always an iteration needed. The idea is that when you want to immobilize / perch the hand shower, ones places its universal butt end into a -- holder clip designed as part of the steel support around the sink rim, or into a -- option 2.) removable extension holder normally stored in the cubbyhole with the hand shower. I'm assuming you can picture a hand-shower thingie, in a kitchen. Made of a typical kitchen pulldown tip. And, also, that you can picture a handshower holder inside the sink, under the counter, in an undermount sink. The hand shower / faucet is then invisible, when stored away. Its hose is too. To get the hose to come from somewhere that make sense, picture a 5" x 24" opening cut out of the counter, along the back wall. This gives you room to reach into garbage and storage below. Cabinets can be pulled forward (e.g. 3") and trimmed down to leave space behind. In that space (behind cabinet drawers) are containers for refuse / garbage / compost, and for the handshower and hose, and for some food (e.g. onions+garlic, root vegetables, bread box / bakery) See "1/6 size" and "1/4 size" restaurant containers (stainless steel, polysulfonate, polycarbonate) 6" deep or deeper. The hose is connected to flex lines behind the counter. In the rim around the sink there is a gap (horizontal slot) greater than 0.75"h 24"w in the steel support (custom built). Under the counter. This gap is where the handles are for IHW, filtered water, and regular tap water. And soap.

Check the specs - they will tell you how far you have. Due to the D shape of my silgranit sink, I was not able to center the faucet over the sink (and window). That actually reminds me why I selected the faucet in the first place! (oh happy coincidence). Sink had been ordered and CT templated and it was time to select the faucet. My original preference was to center the faucet over the sink.... And I think you may be able to as well. If you don't have the room and are left with an off-center faucet -- I think the KK works well. (Broken record here but... Oh do I love this thing!)

Any way of making one joy stick work for both? Probably not, but that would be neat. I know the bigger, kitchen one operates through 180-degrees "north", I don't suppose you could somehow jerry-rig it to send your filter water from the "south" position?? Not really understanding the joy stick at all, I don't know just how stupid an idea that is but I'm willing to believe it is very! But it's a fun idea, you could even call Kohler and suggest it; maybe their engineers would like the idea and work on it?? BTW, short answer from me would be: no. I have a kohler on one sink, another sink nearby with I think it's the Ladylux. I can't see they appear particularly complementary; they were both more heavily functional choices. Nother though re the smaller Karbon - as you wouldn't need to be mixing the hot/cold, maybe you could bypass the joystick for the smaller one, maybe have a kick pedal for on/off or something? Then you'd have two Karbons and one joystick -- that would look, IMO, far better than 2 and 2...

French - I happen to disagree with you on the Karbon. Faulty install is not the manufacturer's fault. I think the finish looks very industrial in the home environment and not cheap at all. This is not the carbon fibre "look" that is slaped on many of today's cars and sporting goods. The one we used had a bit of a matt finish and once you feel it you can tell it's not cheap. The stiffness will wear off after a bit of use, it is a bit anoying out of the box. The drawbacks I see are: the spray pattern is very narrow. To turn off the sprayer requires one to turn off the faucet to re-set. There is no option switch from flow to spray then back again on the spout itself. I concur with erik - the KWC is a good alternative. It's flash and doesn't scream I'm a gorilla, look at me.